1. Field of the Invention
This disclosure relates to an optical coupler having one or more surfaces with a defined degree of roughness for improved optical imaging of target areas by an optical imaging visualization device, such as an endoscope, laparoscope, arthroscope, ophthalmoscope, borescope, or other remote imaging visualization technology.
2. Description of the Related Art
Remote optical visualization devices such as endoscopes and other optical imaging visualization devices illuminate surfaces and other objects a distance from the user of the visualization device, allowing a user to perform a diagnosis or procedure using images and signals generated and transmitted a distance from the observed object. This can include, for example, viewing tissue inside a body cavity or a lumen, inspecting a hydraulic line in an aircraft, inspecting an oil pipeline for leaks, or inspecting a sewer line for leaks and/or blockages. Remote optical visualization devices transmit these images to the viewer in a variety of ways, including, among others, through the use of (i) relay lenses between the objective lens at the distal end of the scope and an eyepiece, (ii) fiber optics, and (iii) charge coupled devices (CCD) and complementary metal oxide semiconductor (CMOS) sensors. Frequently, a video capture system is connected to the optical visualization device to display a video image on a display monitor that can be viewed by a user during use of the optical visualization device, including the ability to adjust the focus of the display through manual adjustments or autofocus capability in a video processor system used with the optical imaging device. To achieve video capture with a video processor system, an objective lens of an optical visualization device focuses light reflected from a target being observed on an image sensor. The image sensor outputs signals based on the detected reflected light. The signals from the image sensor are output to a signal processor, which typically includes imaging software that controls an autofocus feature connected to the objective lens to adjust the in-focus object plane position. A control signal generated by the signal processor activates an autofocus operation to automatically bring the target being observed into focus.
Optical couplers positioned over the objective image capturing element of an optical visualization device allow improved remote observation in areas of the body where visibility has been obstructed by blood, stomach content, bowel content, or other opaque fluids and/or solid particulate matter. Optical couplers also allow improved remote observation in non-medical applications where visibility has been obstructed by fluids and/or solid particulate matter. However, imperfections on the surface of the optical coupler may inhibit the visualization of the optical visualization device, including confusing the signal processor of an optical visualization device using a video capture system, causing the autofocus feature to focus the objective lens on a surface of the optical coupler, rather than on the intended target to be observed. Further, when an optical coupler is used with visualization systems that do not use image capture software, visualization may be hindered when the light from the visualization system passes through imperfections on the distal surface of the optical coupler resulting in increased light reflection and increased glare due to these imperfections. This may occur when light proceeds through the optical coupler and when light returns back through the optical coupler to the scope camera.
It would be advantageous to provide an optical couple that allows improved remote visualization while not interfering with the autofocus feature of a video capture system and not causing increased light reflectance and glare due to improved surface finish.